Abstract: Disclosed is a bulk acoustic wave resonator (BAWR). The BAWR includes a bulk acoustic wave resonance unit with a first electrode, a second electrode, and a piezoelectric layer. The piezoelectric layer is disposed between the first electrode and the second electrode. An air edge is formed at a distance from a center of the bulk acoustic wave resonance unit.

Abstract: A bulk acoustic wave resonator includes a substrate, a first electrode, wherein a cavity is formed between the substrate and the first electrode, a piezoelectric layer disposed on the first electrode and overlapping at least a portion of the first electrode, a second electrode disposed on the piezoelectric layer and overlapping at least a portion of the piezoelectric layer, a passivation layer having at least a portion disposed on the second electrode and overlapping at least a portion of the second electrode, and a lower frame spaced apart from the substrate and having a portion of the cavity disposed therebetween. Any one of the second electrode and the passivation layer includes a protruding portion having a first thickness and an extended portion having a second thickness less than the first thickness, and an inner end of the lower frame and an end of the protruding portion are spaced apart horizontally.

Abstract: A bulk-acoustic wave resonator includes a resonator including a central portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on a substrate, and an extension portion disposed along a periphery of the central portion; and an insertion layer disposed between the piezoelectric layer and the substrate in the extension portion to raise the piezoelectric layer. The insertion layer includes a first insertion layer having a first inclined surface formed along a side surface facing the central portion and a second inclined surface disposed between the first insertion layer and the piezoelectric layer and having a second inclined surface spaced apart from the first inclined surface with respect to a surface direction of the first electrode. The first insertion layer is thinner than the second insertion layer.

Abstract: A bulk-acoustic wave resonator includes a substrate, a resonance portion including a first electrode, a piezoelectric layer, and a second electrode, stacked in this order on the substrate, and a seed layer disposed below the first electrode, wherein the resonance portion includes an active portion disposed in a central portion of the resonance portion, and a lateral resonance suppressing portion disposed to surround the active portion, wherein a thickness distribution of the seed layer, the first electrode, the piezoelectric layer, and the second electrode in the lateral resonance suppressing portion is different from a thickness distribution in the active portion.

Abstract: Provided are a nozzle inspection method and a nozzle inspection apparatus capable of accurately detecting a defect in an inkjet head nozzle within a short time. The nozzle inspection method comprises discharging a plurality of droplets into a first region of interest of a substrate using a first nozzle to form an inspection pattern, and determining whether the first nozzle is defective based on the inspection pattern.

Abstract: A bulk-acoustic wave resonator includes: a substrate; a lower electrode disposed on the substrate; a piezoelectric layer at least partially covering the lower electrode; and an upper electrode at least partially covering the piezoelectric layer. On a surface of the bulk-acoustic wave resonator, a centroid of an active area in which the lower electrode, the piezoelectric layer, and the upper electrode all overlap each other is aligned with a center of a rectangle defining an aspect ratio of the active area. The active area has a shape of a polygon symmetrical with respect to at least one axis passing through the center of the rectangle defining the aspect ratio. The aspect ratio is greater than or equal to 2 and less than or equal to 10.

Abstract: An acoustic resonator includes: a substrate; a resonant region including a first electrode, a piezoelectric layer, and a second electrode disposed on the substrate, and a reflective layer disposed along a periphery of the resonant region; and a connection electrode extending from the second electrode. The reflective layer includes a second section disposed between the resonant region and the connection electrode, and a first section, and a cross-sectional area of the first section is different than a cross-sectional area of the second section.

Abstract: A bulk-acoustic wave resonator includes: a substrate; a membrane layer forming a cavity with the substrate; a lower electrode disposed on the membrane layer; an insertion layer disposed to cover at least a portion of the lower electrode; a piezoelectric layer disposed on the lower electrode to cover the insertion layer; and an upper electrode at least partially disposed on the piezoelectric layer, wherein the upper electrode includes a reflection groove disposed on the insertion layer.

Abstract: A bulk-acoustic wave resonator includes: a first electrode; a piezoelectric layer at least partially disposed on an upper portion of the first electrode; and a second electrode disposed to cover at least a portion of the piezoelectric layer. The second electrode includes a frame disposed at an edge of an active region of the bulk-acoustic wave resonator, and the first electrode, the piezoelectric layer and the second electrode are disposed to overlap one another at the edge of the active region. The frame includes a wall disposed at the edge of the active region and a trench formed on an internal side of the wall. An internal boundary line of the trench has a concave-convex shape in a plane parallel to an upper surface of the frame.

Abstract: A bulk acoustic wave resonator includes: a substrate; a membrane layer forming a cavity together with the substrate; a lower electrode disposed on the membrane layer; a piezoelectric layer disposed on a flat surface of the lower electrode; and an upper electrode covering a portion of the piezoelectric layer and exposing a side of the piezoelectric layer to air, wherein the piezoelectric layer includes a step portion extended from the side of the piezoelectric layer and disposed on the flat surface of the lower electrode.

Abstract: An acoustic resonator includes: a substrate; a resonant portion including a center portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on the substrate, and an extension portion disposed along a periphery of the center portion; and a first metal layer disposed outwardly of the resonant portion to be electrically connected to the first electrode. The extension portion includes a lower insertion layer disposed on an upper surface of the first electrode or a lower surface of the first electrode. The piezoelectric layer includes a piezoelectric portion disposed in the center portion, and a bent portion disposed in the extension portion and extended from the piezoelectric portion at an incline according to a shape of the lower insertion layer. The lower insertion layer is formed of a conductive material extending an electrical path between the first electrode and the first metal layer.

Abstract: A bulk acoustic resonator includes a first electrode disposed on an upper side of a substrate, a piezoelectric layer disposed on an upper surface of the first electrode, and a second electrode disposed on an upper surface of the piezoelectric layer, wherein an upper surface of at least one of the first electrode and the second electrode has a recess region, wherein a depth of the recess region is D, a width of the recess region is W, and a resonance frequency is F, and ln is a natural logarithm, and wherein [{ln(D*W)}/(?0.59*F)] is [[ln{0.008 (?m)2}]/{?0.59*(3.5 GHz)}] or more and [[ln{0.022 (?m)2}]/{?0.59*(3.5 GHz)}] or less.

Abstract: A bulk-acoustic wave resonator includes: a first electrode disposed above a substrate; a piezoelectric layer disposed to cover at least a portion of the first electrode; and a second electrode disposed to cover at least a portion of the piezoelectric layer. A plurality of steps are formed in any one or any combination of any two or more of the first electrode, the piezoelectric layer, and the second electrode in an active region in which the first electrode, the piezoelectric layer, and the second electrode are all disposed to overlap one another.

Abstract: A bulk-acoustic wave resonator includes a substrate, a first electrode disposed on the substrate, a piezoelectric layer covering at least a portion of the first electrode, and a second electrode covering at least a portion of the piezoelectric layer. When an active region, in which the first electrode and the second electrode are disposed to overlap each other, is viewed from above, among four sides of a rectangle with which at least three vertices of a polygon formed by the active region are in contact, a longest side is defined as a side B and a side connected to side B is defined as a side A, and an aspect ratio (side B/side A) is 1.3 to 3.

Abstract: A bulk acoustic wave resonator includes a substrate, a first electrode, wherein a cavity is formed between the substrate and the first electrode, a piezoelectric layer disposed on the first electrode and overlapping at least a portion of the first electrode, a second electrode disposed on the piezoelectric layer and overlapping at least a portion of the piezoelectric layer, a passivation layer having at least a portion disposed on the second electrode and overlapping at least a portion of the second electrode, and a lower frame spaced apart from the substrate and having a portion of the cavity disposed therebetween. Any one of the second electrode and the passivation layer includes a protruding portion having a first thickness and an extended portion having a second thickness less than the first thickness, and an inner end of the lower frame and an end of the protruding portion are spaced apart horizontally.

Abstract: A bulk-acoustic wave resonator includes: a substrate; a first electrode disposed on the substrate; a piezoelectric layer disposed to cover at least a portion of the first electrode; a second electrode disposed to cover at least a portion of the piezoelectric layer; a metal pad connected to the first electrode and the second electrode; and a connection member connected an upper surface of the metal pad. A lower end portion of the connection member includes a tapered portion decreasing in a diameter in a direction toward a lower end of the connection member, and an angle between an inclined surface of the tapered portion and the upper surface of the metal pad is 45° to 80°.

Abstract: A bulk acoustic wave resonator includes: a substrate; a first electrode disposed above the substrate; a piezoelectric layer disposed above at least a portion of the first electrode; and a second electrode disposed above at least a portion of the piezoelectric layer. A first gap is formed between the piezoelectric layer and one of the first and second electrodes. The first gap includes a first inner gap disposed in an active area of the bulk acoustic wave resonator, and having a first spacing distance between the piezoelectric layer and the one of the first and second electrodes, and a first outer gap disposed outwardly of the active area and having a second spacing distance, different than the first spacing distance, between the piezoelectric layer and the one of the first and second electrodes.

Abstract: A bulk-acoustic wave resonator includes a resonator including a central portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on a substrate, and an extension portion disposed along a periphery of the central portion; and an insertion layer disposed between the piezoelectric layer and the substrate in the extension portion to raise the piezoelectric layer. The insertion layer includes a first insertion layer having a first inclined surface formed along a side surface facing the central portion and a second inclined surface disposed between the first insertion layer and the piezoelectric layer and having a second inclined surface spaced apart from the first inclined surface with respect to a surface direction of the first electrode. The first insertion layer is thinner than the second insertion layer.

Abstract: A bulk-acoustic wave resonator includes: a first electrode; a piezoelectric layer at least partially disposed on an upper portion of the first electrode; and a second electrode disposed to cover at least a portion of the piezoelectric layer. The second electrode includes a frame disposed at an edge of an active region of the bulk-acoustic wave resonator, and the first electrode, the piezoelectric layer and the second electrode are disposed to overlap one another at the edge of the active region. The frame includes a wall disposed at the edge of the active region and a trench formed on an internal side of the wall. An internal boundary line of the trench has a concave-convex shape in a plane parallel to an upper surface of the frame.

Abstract: A bulk-acoustic wave resonator includes: a substrate; a first electrode disposed on the substrate; a piezoelectric layer disposed to cover at least a portion of the first electrode; a second electrode disposed to cover at least a portion of the piezoelectric layer; a metal pad connected to the first electrode and the second electrode; and a connection member connected an upper surface of the metal pad. A lower end portion of the connection member includes a tapered portion decreasing in a diameter in a direction toward a lower end of the connection member, and an angle between an inclined surface of the tapered portion and the upper surface of the metal pad is 45° to 80°.